Field of the Invention
The present invention relates to an analytical cell suitable for use, e.g., in an analysis of electrode reactions, etc. using an analytical instrument.
Description of the Related Art
As is well known, in an electric cell, a negative electrode active material and a positive electrode active material undergo electrode reactions, etc. in a charge-discharge process. In recent years, attempts have been made to analyze such electrode reactions during the charging/discharging process using an analytical instrument. For example, Japanese Laid-Open Patent Publication No. 2013-535795 (PCT) proposes an analytical cell which can be observed using a transmission electron microscope (TEM), and a holder for holding the analytical cell.
This analytical cell is formed by providing a negative electrode active material and a positive electrode active material (hereinafter also referred to as the electrode active material, collectively) in an overlapping portion formed by overlapping a pair of substrates. An observation window is formed at substantially the center of the overlapping portion in a direction along the surfaces of the substrates. An electron beam can be transmitted through the observation window in the overlapping direction of the overlapping portion, for allowing observation of electrode reactions, etc. in the electrode active materials. Specifically, a through hole is formed in each of the substrates. The through hole is covered with the transmission membrane from the inside of the overlapping portion. The electron beam can be transmitted through the transmission membrane. The observation window is formed between the through holes which face each other across the transmission membrane.
Further, in the analytical cell, a spacer is provided between the substrates, at an end of the overlapping portion remote from the observation window. In the structure, the substrates are spaced from each other by a predetermined distance. In the overlapping portion, at least one of the electrode active materials is provided between the transmission membranes of the observation window. Each of the electrode active materials is connected electrically to one end of the negative electrode collector or the positive electrode collector (hereinafter also referred to as the collector, collectively), in the overlapping portion. Since the other end of the collector is exposed to the outside of the overlapping portion, each of the electrode active materials is electrically connectable to the charging/discharging devices, etc. outside the overlapping portion through the collector.
That is, in the case of observing the analytical cell using a transmission electron microscope (TEM), firstly, the analytical cell is accommodated in a front end of a holder having a flow channel for allowing electrolytic solution to flow inside the overlapping portion. Thus, the electrolytic solution flows through the flow channel of the holder into the overlapping portion. The collectors are electrically connected to a charge-discharge tester or the like through the electric path of the holder. Consequently, it is possible to cause electrode reactions in the electrode active materials. At this time, an electron beam is transmitted through the observation window for carrying out the TEM observation. In this manner, it is possible to analyze the above electrode reactions.